Bothrops jararaca venom and renal failure: molecular basis of mesangial cell cytotoxicity and the synergistic effect of plasma protein degradation products.

Abstract

In Brazil, snakes of the Bothrops genus are responsible for more than 90% of snakebite cases, in which the clinical outcomes after the bite involve local to systemic effects, with the presence of edema, hemorrhage, necrosis, coagulopathy, and renal failure. Hence, to better understand the mechanisms behind venom toxicity, especially in the kidneys, the general objective of the present project is to evaluate the effects of Bothrops jararaca venom on murine glomerular cells (SV40 MES 13), to explore the participation of these cells in the renal failure observed in cases of envenoming. In addition, we intend to evaluate whether there is a synergistic effect between the products of plasma protein degradation by the proteolytic enzymes of the venom and the role of sialic acid residues in toxins (glycoproteins) that participate in renal pathological effects. To this end, the following specific objectives are proposed: I. To analyze cell viability after exposure to native venom; II. To evaluate the ability of cells to proliferate in response to exposure to native venom at a sub-cytotoxic concentration; III. In the case of decreased cell viability and proliferation, to characterize the type of cell death induced by the native venom; IV. To characterize the morphological changes of cells after exposure to the native venom, by inverted light microscopy and immunofluorescence; V. To analyze the secretome of cells incubated with native venom, or with desialylated venom, or with the native venom together with the plasma peptidome generated by the incubation of the plasma with the native venom, by mass spectrometry (proteins and peptides). By exploring the effects of a venom on renal cells, using quantitative molecular methods allied to immunostaining, this study will contribute to the understanding of the renal tissue response to a complex mixture of toxins (venom), mapping the signaling pathways involved in this response. Furthermore, the poorly studied aspect of the synergistic effect of plasma protein degradation products generated by a venom rich in proteases, as is the case of B. jararaca, may shed light on the concerted action of toxins in the generation of local and systemic pathology of envenomation.